Berry D, Jobe A, Ikegami M, Seidner S, Pettenazzo A, Elkady T
Department of Pediatrics, University of California, School of Medicine, Harbor-UCLA Medical Center, Torrance 90509.
J Appl Physiol (1985). 1988 Jul;65(1):26-33. doi: 10.1152/jappl.1988.65.1.26.
The effect of profound repetitive prenatal asphyxial insults on the cardiopulmonary function of premature ventilated lambs was studied. Twenty-nine fetal lambs (approximately 138 days gestational age) were exteriorized. In 16 of these lambs, the umbilical cord was occluded for 4 min then released for 10 min. This asphyxial episode was repeated until the arterial pH was approximately 7.00, and the mean arterial blood pressure was less than 40 mmHg and falling. The 13 control lambs were simply exteriorized with the umbilical circulation intact. The lambs were then ventilated for 3-4 h. There were no differences between the control vs. asphyxiated lambs in pulmonary compliances (0.57 and 0.58 ml.cmH2O-1.kg-1) wet-to-dry weight ratios (8.18 and 7.55), cardiac outputs (177.8 and 141.8 ml.kg-1.min-1), surfactant-saturated phosphatidylcholine pool sizes, or atrial and/or ductal shunts. Asphyxia did not interfere with the redirection of blood away from atelectatic lung segments created by bronchial obstruction with balloon catheters. Also, although the bidirectional flux of protein into and out of the airways of these preterm lambs was large relative to term lambs, there was no effect of asphyxia on this protein leak. In this animal model, prenatal asphyxia did not impact negatively on the severity of the respiratory failure.
研究了深度反复产前窒息性损伤对早产通气羔羊心肺功能的影响。29只胎羊（妊娠龄约138天）被引出。在其中16只羔羊中，脐带闭塞4分钟，然后松开10分钟。这种窒息发作反复进行，直到动脉pH值约为7.00，平均动脉血压低于40 mmHg且在下降。13只对照羔羊只是引出，脐带循环保持完整。然后对羔羊进行3 - 4小时的通气。对照羔羊与窒息羔羊在肺顺应性（分别为0.57和0.58 ml.cmH₂O⁻¹.kg⁻¹）、湿重与干重比（分别为8.18和7.55）、心输出量（分别为177.8和141.8 ml.kg⁻¹.min⁻¹）、表面活性剂饱和磷脂酰胆碱池大小或心房和/或导管分流方面没有差异。窒息并不干扰通过球囊导管阻塞支气管所造成的肺不张肺段的血液重新分布。此外，尽管相对于足月羔羊，这些早产羔羊气道内蛋白质的双向进出通量较大，但窒息对这种蛋白质渗漏没有影响。在这个动物模型中，产前窒息对呼吸衰竭的严重程度没有负面影响。
